Antenna system



May 16, 1939. w. MOSER El AL ANTENNA SYSTEM Filed March 5, 1937 2Sheets-Sheet 1 INVENTORS ELM MOSERAND HANS ERICH PAUL ATTORNEY PatentedMay 16, 1939 UNITED STATES PATENT OFFICE ANTENNA SYSTEM ApplicationMarch 5, 1937, Serial No. 129,162 In Germany April 28, 1936 6 Claims.

Linear antennas are known whereby two conductors extending parallel toeach other and fed in opposite phase surround each other alternately incertain sections whereby the total radiation is substantially in phase.The surrounding sections are in such known arrangements preferably of alength equal to one half wave length or shorter. Figure 1 shows such aknown construction in which the cylindrical sections a, b, c surround 10the connector sections (1, e, f coaxially. The line is so arranged thatalways a surrounding section is connected with the subsequent innerpiece. Such an antenna may be fed, for instance, at the ends g, h acrossa high frequency transformer i. It is immaterial how the antennastructure is oriented in space whether horizontally, for instance, orvertically.

In cases where further electrical apparatus must be connected with thefar end of the antenna with respect to the transmitter. It is impossibleto arrange its connection lines parallel to the antenna or to otherwiseconnect them in the vicinity of the antenna since the radiation diagramof the antenna would thus be changed in an undesirable manner. Forinstance, it may be desired to supply power to an illumination bulb atthe upper end of the antenna, or to have a further antenna placedthereabove of a different wave length and connected with anothertransmitter or with the same transmitter through a suitable energy line.This problem cannot be solved with the hitherto known forms of suchantennas as far as we are aware. The present invention provides aconstruction by means of which the above problem is solved.

In accordance with the present invention a linear antenna radiating inequal phase is employed which consists of two oppositely fed conductorsarranged parallel to each other, in a such manner known that the firstconductor surrounds the second one and alternately, the second conductorsurrounds the first one. The characteristic feature of the invention ishereby that the conductors enclose a continuous hollow 5 spacesubstantially shielded metallically at the sides for the high frequency.

A better understanding of the invention may be had by referring to thefollowing detailed description which is accompanied by drawings 50wherein:

Fig. 1 illustrates prior art, and

Figs. 2 to 6 illustrate different embodiments of the invention.

Fig. 2 shows, by way of example, a mode of 55 construction of anarrangement in accordance with the invention revealing the fundamentalprinciple of the invention. It should, furthermore. be remarked that theexamples of construction are for a vertical all-around radiatingantenna. However, the idea of the invention may also be similarlyapplied to radiation structures that are otherwise oriented in space.The lowest antenna section is, for instance, so dimensioned that at thisend a current loop, i. e., a voltage minimum appears. At this point theouter conductor or inner conductor may be grounded, and in the same wayas shown in Fig. l. the high frequency energy is applied through atransformer i. In the interior of the surrounding casing a there issituated a further hollow 15 metal tube It metallically connected with aand insulated from the inner conductor d. This tube It forms the innerconductor in the following higher situated antenna section C, and in thethird section cit again rests against the inside of the outer tube withwhich it is metallically connected. In this manner the antenna can beconceived as extended into a suitable number of individual sections. Itcan be seen that no high frequency field exists in the interior of thetubular line k. In accordance with the invention, this line is utilizedfor carrying the insulated through lines. In accordance with the purposeintended, these electric lines pass at both ends into apparatus whichfeed or which are fed. Figs. 3 and 4 show embodiments of the generalidea of the invention in an improved mode as regards arrangement andconstruction. In Fig. 3 two straight tubular through lines In and R12are provided. In accordance with the invention, the 3 hollow space ofeach of the two straight conductors may serve to accommodate therein especially insulated conductor lines.

Fig. 4 shows a construction in which a continuous separate tube 703 isprovided, while the two conductors l and m. surrounding each otheralternately represent cylindrical pieces insulated from and coaxiallyarranged to the tube k3.

Figs. 5 and 6 show arrangements, according to the invention, which showthat the continuous interior hollow spaces serve for receiving theseparate inner conductor connecting the apparatus n and o.

In practical cases the lowest tube is directly connected to ground or apoint of zero radio frequency potential (Fig. 5, point q) or across animpedance (Fig. 6 designated by s) in accordance with the invention. Thelength of the lowest section may be chosen equal to a quarter wavelength. In the figures the ground is represented as metal plate 15.

At the other end a metallic body, for instance, in the form of the metalplate M is provided in accordance with the invention. The apparatus o isthus shielded against the antenna field.

Fig. 6 shows in particular an arrangement, according to the invention,in which two linear antennas are arranged and situated above each otherin the same vertical plane. The lower antenna corresponds exactly withthe hitherto described arrangement and shows the metallic end plates.The feeding takes place through the high frequency transformer i1. Thehollow space It contains a further high frequency energy line n fed atthe bottom through the high frequency transformer i2 and terminating atthe top into a second linear antenna 10 having any desired shape. In thearrangement, according to the invention, the lower and upper antenna areeffectively decoupled. This degree of decoupling can be increased if theupper metal body is given a large surface. According to the invention,by means of such an antenna two waves differing from each other may besent out or received.

Furthermore, in accordance with the invention, one of the two antennasmay radiate, for instance, through transformer i1 into the lowerantenna, and reception may be had by means of high frequency transformeris and the upper antenna.

Furthermore, in accordance with the invention, the upper antenna mayalso enclose an interior space, and may terminate at its upper end intoa third antenna. In this case the lowest antenna must enclose two hollowspaces, according to Fig. 3.

We claim:

1. An antenna comprising a plurality of hol low tubular aerial elementsarranged end to end substantially in a straight line, a two-conductortransmission line for enabling in-phase excitation of each of saidaerial elements, one conductor of said transmission line comprising ahollow tube extending within the hollow spaces of said aerial elementsand throughout the length of said antenna, a source of high frequencyenergy connected to said two-conductor transmis sic-n line, anotherextending within and throughout the length of said one conductor andinsulated therefrom, utilization apparatus at one end of said last line,and a source of energy at the other end of said last line.

2. An antenna comprising several hollow tubular aerial elements arrangedend to end substantially in a straight line, a two-conductortransmission line within said elements, each of the conductors of saidline connected to alternate elements, one of said conductors comprisinga hollow tube and extending throughout the length of said antenna and atransmission line within said tube and insulated therefrom.

3. An antenna comprising several hollow tubular aerial elements arrangedend to end substantially in a straight line, a two-conductortransmission line within said elements, each of the conductors of saidline connected to alternate elements, one of said conductors comprisinga. hollow tube and extending throughout the length of said antenna, asource of high frequency energy connected to said two-conductortransmission line, another line extending with in and throughout thelength of said one conductor and insulated therefrom, utilizationapparatus at one end of said last line, and a source of energy at theother end of said last line.

4. An antenna comprising several hollow tubular aerial elements arrangedend to end substantially in a straight line, a two-conductortransmission line within said elements, each of the conductors of saidline connected to alternate elements, one of said conductors comprisinga hollow tube and extending throughout the length of said antenna, asource of high frequency energy connected to said two-conductortransmission line, another line extending with in and throughout thelength of said one conductor and insulated therefrom, a source of energyat one end of said last line and another antenna at the other end ofsaid last line extending in the same general direction as said firstantenna but resonant to a frequency different from said first antenna.

5. An antenna comprising several hollow tubular aerial elements arrangedend to end substantially in a straight line, a two conductortransmission line within said elements, each of the conductors of saidline connected to alternate elements, each of said conductors comprisinga hollow tube extending throughout the length of said antenna, a sourceof high frequency energy connected to said two conductor transmissionline, another transmission line extending within and throughout thelength of said hollow tubes and insulated therefrom, utilizationapparatus at one end of said last mentioned line and a source of energyat the other end of said last mentioned line.

6. An antenna comprising several hollow tubular aerial elements arrangedend to end substantially in a straight line, a two conductortransmission line within said. elements, each of the conductors of saidline connected to alternate elements, one of said conductors comprisinga hollow tube and extending throughout the length of said antenna, asource of high frequency energy connected to said two conductortransmission line, another line extending within and throughout thelength of said one conductor and insulated therefrom, a source of energyat one end of said last line, another antenna at the other end of saidlast line extending in the same general direction as said first antennabut resonant to a frequency different from said an tenna, and a metallicplate between said antennas, said plate being connected to the uppermostend of said hollow tube.

VVILHELM MOSER. HANS ERICE PAUL.

